last week my pr rank show 4 and now 0 and i have very back links and now show 0 my url www.tinydl.com plz check my site my other page have rank ex: http://tinydl.com/Download_search_engine.html
Here at my Google Toolbar showes N/A Page Rank. Did you do something with your URL structure, changed http to httt://www . I see that your other page don't work and it is without www.
I am also seeing an N/A in this tool, which is very consistent. I checked to see if your site was banned in this tool, and it doesn't appear to be. This may be a temporary thing.